The present invention relates to an instrument set for fixing a cord-like implant in a bone, with a retaining element that can be inserted into the bone, which retaining element comprises a recess for receiving a transverse pin and is also used to fix the implant.
An instrument set of this kind is known from document US 2003/0065391 A1.
In modern surgery, cord-like implants frequently have to be fixed in a bone. In the reconstruction of the ligaments of the knee joint, for example, natural or artificial replacement ligaments are inserted into a channel in the femur and are fixed there by means of a transverse pin. Such a transverse pin is sometimes also referred to as a crosspin.
It is also known to anchor thread loops in a bone by means of a transverse pin and to use these thread loops, for example, to secure detached or torn segments of the rotator cuff to the head of the humerus. This securing can be done directly, that is to say by the thread loops themselves, or by means that are connected to the thread loops.
If cord-like implants of this kind are fixed in a channel in the bone only by means of the transverse pin, without a retaining element, the implant may move to and fro when subjected to loading. This to and fro movement compromises the implant's ability to take and can also lead to a rubbing of the implant on the transverse pin, which in extreme cases leads to a tearing of the implant.
It has therefore been attempted to reduce this to and fro movement by means of a retaining element.
A device and a method for reconstructing a knee ligament are known from document US 2003/0065391 A1 mentioned above. This device comprises a retaining element that has at least two through-openings. The first opening is used to receive the cord-like implant, while the second opening is used to receive the transverse pin.
For the reconstruction of a ligament in accordance with document US 2003/0065391 A1, the implant is guided through the proximal hole, and the retaining element is introduced by means of an applicator into a channel already formed in the femur. In a second step, the retaining element is then anchored in the femur by a transverse pin inserted into the distal hole of the retaining element.
Although the to and fro movement of a ligament in a bone channel can be considerably reduced by such a retaining element, this construction has the problem that the retaining element can be torn apart under high tensile loads, with the result that the ligament comes loose from the retaining element. The transverse pin and the remains of the retaining element then remain in the body.
In this case, these fragments have to be removed, and a new retaining element has to be fitted.
Therefore, an object of the invention is to develop an instrument set for fixing a cord-like implant in a bone it in such a way that a cord-like implant can be fixed in a bone with much greater safety and reliability.